Hi- I'm been lurking here a bit as a designed my tiny travel trailer all fall and winter and now I am getting pumped to start building. I'm gonna use a super duty HF trailer to make a little unit to do some serious road tripping in as the primary goal. Mostly as a solo venture but also for 2 people for on shorter journeys or for camping. One key feature needed to meet these goals is a little potty closet - a stretch for this size I know, but I am 5'6", lol. I am going to make my own SIP to save weight and maximize space. I'm terrified of the whole thing flying apart on the freeway, but weight restrictions from the goal of being able to pull it behind my Outback and the 1750# weight limit of the trailer mean that I have engineering limitations . I'm pleased with my design. I believe that it is going to meet my goals for the project and come in at under $2,000 and under 1,200# . I'll tweak it as it goes. The weight calculations were harder to make than the cost of materials, and that is also something that does have an absolute limit, so it is a concern. I'll have to do my best on that.
Anyway - thanks for being here. I'll Ya posted.